Highway, signal, parking lot and street lighting poles all possess similar features. These cylindrical shaped poles are typically made of galvanized steel, and can occasionally be made of aluminum. The poles are secured onto a concrete foundation, which has a conduit containing wires running through it. These wires continue to the top of the pole where the lighting fixture is located.
Approximately one foot up from the base of the pole, there is a small opening just large enough for a hand to fit in. Through this hole, wires are exposed so that electrical work can be accomplished. The dimensions of the most common holes are 6.5 by 4 inches and 5 by 3 inches, and the shape of the hole is either square or oblong. The holes are also raised away from the surface of the pole so a flat plate can be used as a cover.
There are several plates presently being used to cover the holes, and there is even a universal cover (also known as a shell) which wraps around the face of the pole. All of these replacement covers have a screw or bolt through the plate which tightens to a bracket, and after minutes of tightening the screw, the cover can finally be secured to the pole.
The handhole covers that are presently on the poles create many problems for the companies that use them. Most of the covers have a screw head that protrudes from the face of the cover, which makes it visible and tempting to the general public. Because of this, many covers are tampered with and eventually lost or stolen.
However, the companies that use these covers tried to accommodate for this imperfection, which leads to exposed wires, by tightening down the screws even more. This temporary solution only magnified another problem, which was crushing the wires that get caught between the back bracket of the cover structure and the pole.
Still another problem is that the screw or bolt can freeze to the back bracket from rust, which is caused from small amounts of moisture.
The problem with typical covers is that they present hazards for the general public. Exposed wires in poles are attractive to young children who don't understand the dangers of electricity. Also, crushed wires within poles can cause dangerous conditions at night if appropriate lighting is not provided. For example, many accidents are caused when signal lighting shuts off, because the public doesn't understand laws that apply in such circumstances. Crushed internal wires can also allow electricity to flow through the pole itself, if the pole is not grounded correctly.
Accordingly, a need exists for a handhole cover which is easily used by utility personnel but discourages tapering while also not damaging wires in an interior of the pole.
The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicant's acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.
______________________________________ PATENT NO. ISSUE DATE INVENTOR ______________________________________ 4,914,258 April 3, 1990 Jackson ______________________________________